The present invention is directed to the preparation in pure state of organosilane compounds containing at least one amino substituent and at least one oxyaliphatic or oxyaromatic group attached directly to silicon. The invention includes the compounds thus formed, the methods of making them and the polymeric products obtained by their reaction with certain silicone polymers.
The relatively uncomplex molecules which can be described as mixed organoalkoxyaminosilanes and alkoxyaminosilane hydrides have not heretofore been isolated as pure materials, nor have such compounds been characterized. Prior publications offer evidence that compounds of this class could not be isolated as pure products since they were subject to random scrambling reactions (See Moedritzer, K. and Van Wazer, J. R., Journal of Inorganic Nuclear Chemistry 26:737 (1964); Inorganic Chemistry 3:268 (1964); Inorganic Chemistry 7:2105 (1968). These authors reported in the cited 1968 reference, for example, that the following is an equilibrium reaction: EQU 2 Me.sub.2 Si(OMe)(NMe.sub.2).revreaction.Me.sub.2 Si(OMe).sub.2 +Me.sub.2 Si(NMe.sub.2).sub.2
wherein Me is a methyl group (--CH.sub.3). They were unable to obtain spectra of the pure compounds since they could not isolate these, but they did make assignments based on the obtained mixtures.
The first of the above-cited publications discloses calorimetric and kinetic results indicating that the presence of a methyl group increased the rate of exchange 20 to 200 fold. When two or more methyl groups were present, the exchange rate was so great that these authors could not measure it. The distribution of alkoxy and amino groups on the silanes was shown to be random. In the case of the mixed chloroaminosilanes, on the other hand, although exchange was reported, the distribution appeared to be non-random. From the foregoing evidence, it would appear, although unlikely, that the mixed chloroaminosilanes might be isolated, while the mixed alkoxy aminosilanes certainly could not be isolated. One of the present inventors indeed was able to isolate and distill mixed chloroaminosilanes (Washburne, S. S. & Peterson, W. R., Inorganic Nuclear Chemistry Letters 5:17 (1969). Initial attempts to prepare the mixed alkoxyaminosilanes, however, were not fruitful, thus substantiating the evidence presented by Moedritzer and Van Wazer in support of their argument that such preparation of the pure mixed alkoxyaminosilanes was not possible.